Nick Pickles. Really. Who is writing this?

Some ideas. DECLAS seems too obvious and limited.

D-1: NCAA Sports Div 1. Dopamine Type 1.

E-2: Investor Visa. E-2 Hawkeye - early warning aircraft.

C-3: Command, Control, and Communication. C3 explosive (77% RDX, 23% explosive plasticizer)

L-4: micokernal for Unix-like opertaing system. Lagrange Point L-4 (point of gravity balance between earth and moon)

A-5: A-5 Vigilante nuclear strike bomber(ret 1979). Apple A5 Chip System. Samsung Galaxy A5 smartphone.

S-6: Witness Visa. Samsung Galaxy S6 smartphone